The present invention relates to an applicator for a releasing agent. More particularly, the present invention relates to an apparatus for applying a releasing agent such as a silicone oil to a fixing roller of a copying machine such as a plain paper copy machine.
FIG. 1 illustrates a conventional fixing portion of a copy machine. In such a machine the releasing agent is applied to a fixing roller 1 and to a pressure roller 2. The releasing agent prevents adhesion of toners 4 to the fixing roller 1 and twining of paper 3 around the fixing roller. Typically, dimethyl polysiloxane for example, KF #96 manufactured by Shine-estu Silicone Co., Ltd. or SH 200 manufactured by Toray Silicone Co., Ltd., have been used as releasing agents.
In recent copy machines the amount of silicone oil has been generally reduced. The reduction saves on the amount of silicone oil used, minimizes spotting of the copy paper 3 and reduces formation of silicone oil spots on the portion adjacent to the fixing roller 1. To reduce the amount of silicone oil used, it is usual to apply the silicone oil by passing it through a material such as tetrafluoroethylene resin porous material; for example, Poreflone.RTM. manufactured by Sumitomo Denko Co., Ltd.
However, reducing the amount of silicone oil applied is difficult. For example, if the amount of silicone oil applied is excessively small, a lack of silicone oil results when copying under severe copying conditions such as when copying is continued for a long time period or the document to be copied is of the type requiring a large amount of toner. Such conditions result in the toner 4 being undesirably stored at the front portion of blade 6 and a portion of the stored toner passing the blade 6 causing unwanted spots on the picture being reproduced on the copy paper.